Skip deleted files in git cl format

BUG=577647

Review URL: https://codereview.chromium.org/1644973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@298449 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -3529,6 +3529,8 @@ def CMDformat(parser, args):
   changed_files_cmd = BuildGitDiffCmd('--name-only', upstream_commit, args)
   diff_output = RunGit(changed_files_cmd)
   diff_files = diff_output.splitlines()
+  # Filter out files deleted by this CL
+  diff_files = [x for x in diff_files if os.path.isfile(x)]
 
   clang_diff_files = [x for x in diff_files if MatchingFileType(x, CLANG_EXTS)]
   python_diff_files = [x for x in diff_files if MatchingFileType(x, ['.py'])]